In this type of motor control device in the related art, the one has been proposed which determines a failure condition when a current deviation between a measured motor current detection value and stored motor current command value exceeds a predetermined determination threshold value, and thereby blocks a motor output by setting the motor current command value to “zero” (for example, refer to PTL 1 and PTL 2).
In the motor control device disclosed in the above-described Patent Literature in the related art, even if there is the failure condition, such as a short circuit failure in armature winding and a ground failure in wiring between the control device and a motor, when power supply voltage drop resulting from voltage fall due to an abnormal current upon the failure is less, if there is a sufficient voltage value required for operating an in-vehicle electric power steering control device, it is still possible to identify a normal driving condition and the failure condition.